Lull 1044C-54 Series II Service Manual User Manual
Page 338
Transmission
8-14
31200079
Normal Operation of the transmission is as follows:
When the boom is not above 20°, the transmission shifts normally (i.e., the
gear selected using the Transmission Shifter is the gear the transmission
shifts to).
When the boom is above 20° and not above 40°, the transmission is limited
to first and second gears. Selecting first gear will put the transmission in
first gear and selecting any other gear will put the transmission in second
gear.
When the boom is above 40°, the transmission is disabled.
When the boom is above 40° and the Transmission Disconnect Override
Footswitch is activated, the transmission will operate in first gear only
regardless of the gear selected with the Transmission Shifter. This is an
extremely dangerous operation – see the Operator's Manual for more
information on this.
Troubleshooting the transmission: If the transmission is not operating as described above, check the
following items:
1. Check the 7.5 amp transmission fuse (F3) on the circuit board in the
cab. If the fuse is blown, replace it with another 7.5 amp fuse. If it blows
again immediately, there is an electrical short somewhere in the
system that must be corrected. Never replace the fuse with one of a
larger amp rating or a fire or other permanent damage to the electrical
system may occur.
2. Check that power is being supplied to the Transmission Shifter at pins
1 and 9.
3. Check that Diodes D1 through D9 are installed in the proper direction
and are functioning properly (they can be tested using a digital
multimeter with a diode mode).Replace any failed diodes that are
found.
4. Check that Relays K11 through K17 are operating properly. Replace
any failed relays that are found.
5. Check the Diode Modules on the harness assembly part number
4923243. If there are failed diodes in the diode module, replace the
internal circuit board with the diodes on it.
6. Check the condition of the wires on each of the harnesses that make
up the transmission shift circuits. See part numbers 4923246, 4923242
and 4923243. If there are damaged wires or loose connections, repair
as necessary or replace the harness.